Hooking up my JL sub


Folks - I need a little help. Trying to figure out best possible way to connect my JL Audio F112 sub to my Marantz AV7005 processor/preamp. 
Signal is coming from Benchmark DAC 1 - yes I know it’s a preamp and yes I love the sound directly from it - except that there is no remote volume control and I am lazy. 
Passing signal to my Marantz in Pure Direct mode cuts the signal to the subwoofer. Can I use a RCA Y splitter and pass one signal to Marantz and the other to JL audio? 
ghulamr
Yes. But a Line Out Converter might be a better solution. The LOC connects to your amps speaker out and drops the signal down to line level allowing you to use the subs RCA inputs. Parts Express has one for under $10.
Great idea. I like that better as the tonal characteristics of the Simauido W5 amplifier is not lost and both the Von Schweikerts VR4 and the sub will be in sync. Do I simply unplug the RCA inputs at the sub and let the XLR input on the mono remain on the sub when I switch Marantz to watch movies? 
@millercarbon. Thanks BTW. Stupid question: is there a decent grade LOC unit that you recommend? Also, a few I saw online have a bunch of color coded wires sticking out. Which wires connect to the R/L of the amp speaker output.